The Spinetingler series does not have a new book coming out soon. The latest book, Saber-Toothed Tiger (Book 30), was published in February 1998.
The first book in the Spinetingler series, The Substitute Creature, was published in March 1995.
The Spinetingler series primarily falls into the Horror genre. This middle grade series was written for ages 8-12, but can be enjoyed by older readers as well.